How do you reduce sample size in clinical trials? Reducing sample size without losing power can be accomplished in one of three principles. This paper examines these methods and demonstrates 15 ways to reduce sample size in clinical trials.

The terms superiority, equivalence and non-inferiority are used frequently in publications on clinical trials. To someone starting out in clinical research these three terms and their precise meaning can be quite difficult to grasp. Indeed even experienced researchers have trouble getting their head around these hypotheses. So, what do these terms mean?

N-of-1 trials are the application of the machinery of randomised clinical trials to the individual patient. Episodes of treatment rather than individual patients become the fundamental unit of inference and patients are repeatedly randomised to an experimental and a control treatment (say) in order to establish the effect of treatment. Popular designs involve cycles of episodes of treatment with the patient being assigned to a random order within cycles.(Continued below)

Statsols looked at data from 220,000 clinical trials. Below are just some of the points we found.

As you may know, Section 801 of the Food and Drug Administration Amendments Act (FDAAA 801) requires the registration and submission of summary results of clinical trials with ClinicalTrials.gov. The law applies to certain clinical trials of drugs (including biological products) and medical devices. At the time of publishing ClinicalTrials.gov currently has over 220,000 clinical trials registered. We examined the data to get some interesting results on a few topics such as: